Controlled fermentation has long been one of the objectives in the vegetable salting industry, such as cucumber pickling. For years, the chemical, bacteriological and physical phenomena involved in the manufacture of, say, salt stock from green cucumbers by natural fermentation in brine, have been studied fairly definitively as has conversion of the salt stock to sweet, sour and mixed pickles followed by pasteurization and canning. This is likewise true of brine preservation of green beans, carrots, green tomatoes, okra, peppers, corn, and other vegetables and fruits, e.g., olives.
These studies quite naturally took into consideration salt concentrations and control thereof during brining and curing so that proper media for resultant microorganism activity could be effectively provided. It was found, for example, that among the microbial groups which grow during fermentation, sufficient salt-tolerant bacteria must be present to provide for the production of fermentation acids. The predominant acid is lactic acid, with a small amount of acetic acid being present. Obviously, the size and variety of cucumbers being pickled, brine temperature, general environmental conditions, and the like, are important to proper fermentation. It is also very important to avoid brine stock spoilage, including bloating and softening. Absence of proper conditions for the development of brine acidity can deleteriously affect the salt stock and the finished pickle products, such as dills, relishes, sours, sweets, and hamburger slices.
It can be appreciated, for example, that the brining of cucumbers for salt stock purposes in the South, such as the South Atlantic States, has generally been conducted in an environment which is significantly warmer than that in which similar brining procedures are carried out in the northern areas of the country, usually Midwestern States. One of the factors which has been of substantial concern is that the rate of lactic acid formation can vary greatly from area to area and even from vat to vat. Further, what is the effect of the traditional use of an inflexible schedule in which dry salt is introduced into the fermentation-brine solution throughout the salting operation? While much has been written about the desirability of controlling the brine concentration throughout the salt stock production, what effect does this have on the bacterial growth rate? For instance, it has been pointed out that brine acidity resulting from microbial activity develops more readily using low initial salt concentrations. On the other hand, high initial salt concentrations retard growth of lactic acid bacteria and consequently less acid is formed.
As is suggested from these facts and others prevalent in the literature, proper control of fermentation throughout the salting operation has been the subject of a great deal of concern. Accordingly, the present invention is directed to providing a means of control using brine acidity as the monitor to effect rapid and simple determination of the brine acidity.
A still further object of the present invention is a simple procedure for enhancing fermentation under varied conditions, such as conditions of temperature, brine concentrations, vegetable (e.g., cucumber) sizes, vegetable varieties, time of harvest, microbial flora, geographical area and the like.
Of interest in this regard are the following literature and patent references:
Jones, I. D., Industrial and Engineering Chemistry, 32, No. 6, 858-861 (1940). PA1 Etchells, J. L., and Jones, I. D., American Journal of Public Health, 36, 1112-1122 (1946). PA1 Etchells, J. L., Jones, I. D., and Bell, T. A., 1950-1951 Yearbook of Agriculture, 229-236 (1950). PA1 Etchells, J. L., Bell, T. A., and Williams, C. F., Food Technology, 204-208, (May, 1958). PA1 Etchells, J. L., and Moore, W. R., Jr., Pickle Pak Science 1:1-17 (1971) published by Pickle Packers International, Inc. PA1 U.s. pat. Nos. 3,480,448; 3,420,676; 3,410,755; 3,403,032; 3,374,099; 3,051,661; 2,905,594; 2,345,814. PA1 West Germany: 1,199,023; 1,115,476. PA1 Fossum, J. H., Markunas, P. C., and Riddick, J. A., Analytical Chemistry, 23, No. 3, 491-493 (1951). PA1 Whitehead, T. H. Journal of Chemical Education, 36, No. 6, 297 (1959). PA1 Bell, T. A., Etchells, J. L., and Kelling, R. E., Journal of Food Science, 36, 1036-1038 (1971).
Insofar as the standard used herein is concerned, viz., tris(hydroxymethyl)aminomethane, the following references are likewise of interest: